1. Technical Field
The present invention relates to a manufacturing method of a drift tube which is used for a drift-tube-type accelerator, and to the drift tube.
2. Description of the Related Art
A drift-tube-type accelerator is provided with, inside a cylindrical tube, a plurality of drift tubes disposed at intervals on and along the central axis of the tube (e.g., see Japanese Unexamined Utility Model Application, Publication No. Hei 4-108900). Each drift tube has an annular shape with a through-hole formed at the center part, and magnets for generating magnetic fields are embedded on the outer circumferential side of the through-hole. This drift tube is suspended by a rod-like stem from the upper side of the tube so that the through-hole is positioned on the central axis of the tube.
In such an accelerator, a particle beam such as a proton beam and an ion beam generated by a beam generator is accelerated inside the tube and fired at a target to thereby carry out experiments and the like. At this time, since otherwise the particle beam is diffused inside the tube, the particle beam is directed through the through-hole of the drift tube so that the particle beam is focused by the magnetic fields generated by the magnets.